Recently various kinds of radio telephones have been developed. One of these is generally referred to as a mobile telephone. The mobile radio telephone, which may be mounted in a car, a train, a ship or the like, comprises a transceiver unit with an antenna and telephone unit including a handset and a base unit. These units are physically separated and are connected by signal lines to one other. Another kind of radio telephone is referred to as a portable telephone. Portable telephones may be further divided into two groups: a transportable type and a handheld type. In the transportable type of portable radio telephone, a transceiver unit is combined into a main unit of a telephone unit and an antenna is attached to the main unit, consequently a user may carry the transportable telephone wherever the user goes. In the handheld type of portable radio telephone, all components are compacted into one unit which may be held in the hand of a user. All of these radio telephones are supplied with power from a battery.
Generally, it is required to reduce consumption of electric power since its power is supplied from a battery installed therein or in a vehicle, which has a limited power capacity.
Although the power of the battery is consumed whenever the radio telephone is turned on, additional power is consumed whenever a ringer tone must be generated in response to reception of a call from another party. Because power is needed to drive a loud speaker for generating the ringer tone, it is desirable to reduce either the number of times or the ringing period when calls from other parties are received. Especially, in the case of a portable phone, which has only a limited power capacity owing to miniturization therefor, the consumption of battery power is a serious problem. For example, when only limited power capacity is remaining and a call from a third party, which may not even be an important call, is received, the power of battery may be immediately consumed due to the necessary generation of ringer tone. Consequently, a user becomes unable thereafter to subsequently make or receive a call. Even in the case of a mobile telephone in a car, whenever the car is parked and the mobile telephone is left turned on without being attended by another party, if calls from anyone are received, the power of the battery is wastefully consumed.
Although the user may think to turn off the power supply in these cases, it will be impossible for the user to receive an important call or an emergency call.
Yet, in some situations the user may intentionally wish to prevent reception of incoming calls. For example, the user may wish to turn off power to the telephone while the user is attending a meeting or the like thereby preventing reception of incoming calls. Also in such a case, it is desirable for the user to be capable of receiving an important call or an emergency call.
In prior art telephone apparatus, repertory dialing is well known. For repertory dialing, the user may store a personalized repertory dialing list including a plurality of frequently called numbers is stored in a memory of the apparatus. A user may make a call to one of the frequently called numbers by inputting an abbreviated data code corresponding to a called number. When a user receives calls from other apparatus, the repertory dialing list may be thought to be useful in distinguishing an important incoming call or an emergency call from the other calls because the contents of the two lists may be similar. However, it is necessary for call restriction to identify the unique identification number of calling apparatus. Prior art radio telephone apparatus equipment with repertory dialing features is not configured to identify, nor do known radio telephone systems provide to a called apparatus, a telephone number for each calling apparatus.